0

Guest

Courses New

A car covers its outward journey at 40kmph. It is towed back, over exactly the same distance at 10mph. What is the average speed over the entire journey? A)12mph B)14mph C)15mph D)20mph Ans :D

A car covers its outward journey at 40kmph. It is towed back, over exactly the same distance at 10mph. What is the average speed over the entire journey?
 
A)12mph B)14mph C)15mph D)20mph
 
 
Ans :D

Grade:10

2 Answers

Arun
25750 Points
6 years ago
Dear student
 
we can apply the formula 2xy/(x+y) for average speed.
Hence
 
Avg speed = 2*40*10/(40+10) = 800/50 = 16 kmph
 
Regards
Arun (askIITians forum expert)
Arun
25750 Points
6 years ago
 
Sorry,the above soltuion is incorrect due to not taking conversion
 
40 kmph = 40/1.6 mph = 24.85 mph
 
Now avg speed = 2*24.85*10/34.85 = 14.26 mph
 
Hence option B is correct

Think You Can Provide A Better Answer ?

Other Related Questions on 10 grade maths

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More